Electrolytic metal hydroxide cell



May 4, 1965 P. s. ROLLER 3,182,010

ELECTROLYTIC METAL HYDROXIDE CELL Filed March 24, 1961 2 Sheets-Sheet 1 INVENTOR Paul 8. Roller FIG.3. BY

ATTORNEY May 4, 1965 P. s. ROLLER 3,132,010

ELECTROLYTIC METAL HYDROXIDE CELL I Filed March 24, 1961 2 Sheets-Sheet 2 INVENTOR Paul 3. Roller ATTORNEY 3,182,010 ELECTROLYTIC METAL HYDROXTDE CELL Paul S. Roller, 4021 9th St. NW., Washington, DC. FiledMar. 24, 1961, Ser. No. 93,070 8 Claims. (Cl. 204-427) The invention relates to improvements in electrolytic cells for generating metal hydroxide.

When current is pased to the metal anodes of a cell immersed in water or in an aqueous solution near the neu tral point, the metal of the anode is converted into insoluble metal hydroxide. In order that this reaction shall proceed efficiently, an important requirement is that the electrode plates shall be wiped during the electrolysis, as set forth in my copending application Serial No. 615,218, filed October 8, 1956, now U.S. Patent No. 3,006,826.

An object of the invention is to provide a wiper for the electrode plates of a metal hydroxide producing cell in which the wiping tension is maintained substantially constant, despite continued thinning of the plate due to loss of metal resulting from its conversion to metal hydroxide.

Another object is to provide a wiper for such a cell which is based upon springs rather than rubber for the required elasticity.

Still another object is to provide a cell of highly economical construction consistent with a required low cost of operation, such as in the purification of water.

With these and other objects in mind, as will become more apparent hereinafter, for a better understanding of my invention reference is made to the accompanying drawing wherein like reference character indicate like parts throughout the several figures, and in which:

FIG. 1 is a cross-sectional view taken axially of an electrolytic cell in accordance with the present invention;

FIG. 2 is a cross-sectional view taken on line 2-2 of FIG. 1;

FIG. 3 is an enlarged fragmentary cross-sectional view taken on line 3-3 of FIG. 2;

FIG. 4 is a cross-sectional View taken on line 4-4 of FIG. 2;

, FIG. 5 is a plan view of one form of plateto-bus contactor;

FIG. 6 is a plan View of an alternate form of said contactor;

FIG. 7 is a plan view of a spider taken along line 7-7 of FIG. 1; and

FIG. 8 is a perspective view of a spacer for the wiper arms.

Referring now specifically to the drawings, housing 10 for cell 32 may be of any suitable shape, but i shown herein in the form of a cylindrical tank having flanged heads 12 and 13 and provided with a water inlet 14 and an outlet 15. Sets of four lugs 16 extend inwardly of said housing adjacent each end thereof, and the four arms 19 of a spider 17 are attached to the respective lugs of each set by fasteners 18 comprising for example a bolt and nut. The four arms 19 of spider 17 are each provided with a collar 21 having an insulating bushing 21 therein.

Bus rods 22 pass through the bushings 21 of the two spiders 17 and are secured to said spiders while insulated therefrom by a suitable fastening, such as by nut 23, metal washers 24 thereunder and insulating washers 25 over said bushings.

Current leads 48 and 48 passing into tank 1th through insulating bushings 11 thereon are connected to each of two said bus rods 22, or a multiple thereof in parallel, conveniently by connection at metal washer 24 and nut 23.

An electrolytic battery or cell 32 within housing 10 comprises a plurality of similar electrode plates 33 mounted in parallel conformation on the four bus rods 22 and separated in mutual equal spacing by annular insulating spacers 34 on said bus rods.

1' nited States Patent 0 Each plate 33, preferably in the form of a square with truncated or rounded corners, has a plurality of openings 39, normally four said openings, near the margin of the corners or modified corners of the square. Three of the four openings 39 of each plate are provided with tight fitting bushings 41, and the fourth opening 39 is bored to provide a recess 42 surrounding said opening. A conducting contactor 43, which is preferably a modified metal washer or collar as to be more specifically described, is fixed in said recess. The spacers 34 are situated over said openings 39 and are at least wide enough to cover said contactor 43.

The bus rods 22 pass through said bushings 41 of the mounted plates 33 and also pass through said contactors 43 while bearing against them. Said contactors are aligned alternately on alternate rods 22 to which said current leads 48 and 48' are attached respectively. Each said contactor, bearing against a plate 33 and a rod 22, provide an electrical current conducting path between said plate and rod. As a resultant of the alternate placement of said contactors and the conducting engagement there of half the plates 33 are anodes and the other half are cathodes.

As an alternate construction yielding the same anode and cathode relation, instead of three insulated bus rods 22 there may be only two such rods while the other two rods 22 passing through contactor 43 are placed in parallel.

One form of contactor 43, shown in FIG. 5, comprises a Washer 44, the rim of which is in contact with the wall of recess 42, having projections or prongs 45 on the inner margin thereof. Said projections are preferably bent back slightly against bus rod 22 and are in resilient pressure contact with it.

An alternate form of contactor 43, shown in FIG. 6, comprises a split washer 46, a portion of the rim of which is in contact with the wall of recess 42 while elsewhere the width of the washer narrows in approaching the washer gap 47. The narrowing provides clearance of a portion of the outer rim of said washer with respect to the wall of recess 42. Bus rod 22 expands said washer at the clearance and is thus in resilient pressure contact with it.

Plates 33 have central apertures 40 through which drive shaft 26 passes freely.

Said drive shaft is connected by coupling 28 to gear box 27 which is in turn connected to motor 29. It passes axially into housing 11) through a stufiing box 3% on tank head 12 and is journalled in bearings 9 on spiders 17.

A wiper assembly 35 is carried by shaft 26 between each pair of adjacent plates 33. Each said wiper assembly includes a revolvable arm 36 having a key-end 37 shaped to conform to shaft keyway 31 and in which said arm is slidably engaged to said shaft. Said keyway is preferably T-shape, as shown in FIG. 2, insuring that arms 36 are held securely in said shaft against the outward centrifugal force of rotation. Keyway 31 alternately may be tapered toward the circumference in order similarly to secure arm 36.

The revolvable arms 36 are centered between plates 33 by the symmetrical construction of said wiper assembly. For positive centering spacers 38 are employed. Shaped similarly to keyway 31, as shown in FIG. 8, said spacers may be slidingly fitted into said keyway with the end spacers 38 resting against bearings 9.

With respect to any pair of adjacent plates 33 and the wiper assembly 35 situated therebetween, a wiper 49 touches one of said plates while a second identical wiper 49 touches the other. Wipers 49 if sufficiently flexible may be supported directly by a plurality of springs, such as fiat springs 51 and 54. More generally, wipers 49 are 3 held to a suitable wiper support, which in turn is attached to said springs.

One form of support may comprise simply rigid flat strips. Preferably, the wipers 49 are supported by holders 50 and 50' which are identical in said wiper assembly but turned oppositely to the opposite of two adjacent plates 33. Both said holders are connected to arm 36, and in the preferred construction are oppositely disposed to said arm, although they may also be on the same side thereof.

Springs 51, fastened together at one point to arm 36, one above said arm and the other below in any suitable manner as by rivet 52, connect the far ends of said holders to the far end of said arm. Springs 54, similarly fastened together at one point to said arm as by rivet 52, connect the rear ends of said holder 54 to the rear end of said arm. The attachment of springs 51 and 54 to holders 50 and 50' is made at the bottoms thereof in any suitable manner, as by an eyelet 53 formed out of said bottoms.

The azimuthal displacement of holders 50 and 50' from arm 36 is as great as possible in order that springs 51 and 54 may be desirably as long as possible. The azimuthal distance between each said holder and said arm may for this purpose be as high as 45 degrees.

While arm 36 is radial to shaft 26, holders 50 and d are preferably somewhat off-radial and in a direction toward parallelism with said arm. The sweep of wipers 49 is thereby directed outward to the periphery of plates 33, and displaced matter is dispersed to the periphery rather than toward the center.

Each wiper 49 is formed of any suitable wiping material such as rubber, plastic, cellulose-derivative, or other compound adapted for wiping when under spring pressure. Preferably, wiper 49 is in the shape of a wedge or triangular prism having an edge 57 touching a plate 33, whereby wiping is effected with a minimum of frictional resistance. Each holder 50 or 51' conforms to the shape of wiper 49 but is truncated to permit insertion of said wiper in the corresponding opening. Holder 50 or 50' is preferably of thin flexible material which can be sprung to clamp wiper 49 in place.

Because springs 51 and 54 tend to push adjacent plates 33 apart during assembly of said plates, the insulated spacers 34 may be provided with threaded holes 58, and set screws 59 therein that are forced against bus rods 22 in order to hold two or more of said plates in place during the assembly.

Cell 32 is terminated by insulated backing plates 60 provided with openings corresponding to those of plates 33. The entire assembly of said plates is held firmly together by the end locking effect provided by spiders 17 and nuts 23.

It is evident that while the assembly of cell 32 has been indicated as being made in housing 10, said cell may also be pre-assembled, substantially in the manner as described, and then inserted as a unit in said housing.

The arms 36 are revolved during electrolysis by the IQ? tation of shaft 26, causing wipers 49 to sweep across plates 33 and displace the soft gel film thereon prior to its hardening. Springs 51 and 55, being similar and of equal length, cause the wiping pressure to be evenly distributed along the length of wiper 49. The magnitude of the Wiping pressure is regulated by the selected bending moment of springs 51 and 54.

Springs 51 and 54 are initially bent back from plates 33, as shown in FIG. 3. As the plates thin down due to loss of metal, the bend will decrease, but will still be present at the utmost thinning of the plates whereby continuing wiping pressure is maintained.

When the thickness of plates 33 is high relative to the distance of separation of the plates, the angle of spring bend will have changed considerably at utmost thinning of said plates. The construction as hereinabove set forth permits springs 51 and 54 to be made long, whereby despite an appreciable change in angle of bend, the spring tension and therewith the effectiveness of wiping, will be maintained substantially constant up to utmost thinning of plates 33, v

lthough certain specific embodiments of the invention have been shown and described, it is obvious that many modifications thereof are possible. The invention, therefore, is not to be restricted except insofar as is necessitated by the prior art and by the spirit and scope of the appended claims.

Having thus described my invention, I claim:

1. An electrolytic cell for metal hydroxide production, comprising a plurality of parallel metal electrode plates, and a wiper assembly between each adjacent two said plates and including a support disposed parallel with and intermediate said plates, means for driving said support through a path parallel with and intermediate said plates, two resilient means carried by said support and respectively biased toward the opposed surfaces of said adjacent plates, and a wiper carried by each of said resilient means and resiliently urged thereby with substantially constant wiping pressure against the respective plate surfaces toward which the respective resilient means is biased.

2. An electrolytic cell according to claim 1 wherein each said resilient means comprises flat spring means secured to said support and including two branches having free ends biased toward the opposed surfaces of said adjacent plates, said wipers being mounted on the free ends of said branches, and the wipers of each of the said branches being mounted oppositely and being disposed in opposite directions for engagement with said opposed plate surfaces.

3. An electrolytic cell according to claim 1 wherein each said resilient means comprises two branches each including at least two flat springs secured to said support, said branches having free ends biased toward the opposed surfaces of said adjacent plates, said wipers being mounted on the free ends of said branches and said branches mounted on opposite sides of said support.

4. An electrolytic cell according to claim 1 wherein said plates each have a central aperture, said support drive means comprises a rotatable drive shaft extending through said apertures perpendicular to said plates, and said supports comprise arms extending radially of said shaft.

5. An electrolytic cell according to claim 1 wherein said plates each have a central aperture, said support drive means comprises a rotatable drive shaft extending through said apertures perpendicular to said plates, said supports comprise radial arms connected to said shaft and floating arms extending laterally from said radial arms and connected to them by resilient means, and said wipers carried on said floating arms.

6. An electrolytic cell for metal hydroxide production, comprising a plurality of parallel metal electrode plates each provided with at least two marginally disposed openings with a recess in one side of each plate surrounding at least one of said openings, the other of said openings provided with insulating bushings, a conducting contactor in each said recess resiliently bearing against the wall thereof, said plates being oriented with their openings in alignment and their bushings and contactors disposed alternately in the given alignment thereof, at least two conducting rods respectively passing through said aligned openings and resiliently engaged by said contactors, whereby alternate plates are in conducting engagement with the respective said rods, a plurality of annular insulating spacers on said rods between adjacent plates and covering said openings and said recesses, said plates being equally separated by the thickness of said spacers, and end locking means on said rods to hold said plurality of electrode plates firmly together.

7. Claim 6 wherein said contactor is a thin metallic washer having projections on the inner margin thereof which press against said rod. 7

8. Claim 6 wherein said contactor comprises a split washer, the Width of said Washer narrowing toward the gap thereof, whereby said washer is expanded by said 5 rod passing through it.

References Cited by the Examiner UNITED STATES PATENTS 6 3/37 Holland 204-227 4/46 Negus 204227 8/52 Williams 1S250.32 10/61 Roller 204-149 FOREIGN PATENTS 9/60 France. 1888 Great Britain.

JOHN H. MACK, Primary Examiner. JOSEPH REBOLD, Examiner. 

1. AN ELECTROLYTIC CELL FOR METAL HYDROXIDE PRODUCTION, COMPRISING A PLURALITY OF PARALLEL METAL ELECTRODE PLATES, AND A WIPER ASSEMBLY BETWEEN EACH ADJACENT TWO SAID PLATES AND INCLUDING A SUPPORT DISPOSED PARALLEL WITH AND INTERMEDIATE SAID PLATES, MEANS FOR DRIVING SAID SUPPORT THROUGH A PATH PARALLEL WITH AND INTERMEDIATE SAID PLATES, TWO RESILIENT MEANS CARRIED BY SAID SUPPORT AND RESPECTIVELY BIASED TOWARD THE OPPOSED SURFACES OF SAID ADJACENT PLATES, AND A WIPER CARRIED BY EACH OF SAID RESILIENT MEANS AND RESILIENTLY URGED THEREBY WITH SUBSTANTIALLY CONSTANT WIPING PRESSURE AGAINST THE RESPECTIVE PLATE 